This is a 30-year-old woman scanned at 35 weeks of gestation. The previous ultrasound scans were normal. The current ultrasound examination revealed a small thick-walled urinary bladder and bilateral hydronephrosis. The amniotic fluid was normal and the fetal growth and placenta were also normal.

The baby was delivered normally at 39 weeks of gestation and the diagnosis of posterior urethral valves was confirmed.